Memory devices are used in many applications, such as computers, calculators, and cellular phones, as examples. Packaging of memory devices varies in different applications. For many years, single in-line memory modules (SIMMs) were used in computers. However, beginning with memory used for more recent 64-bit processors, dual in-line memory modules (DIMMs) have become more common. DIMMs have separate electrical contacts on each side of the module, while the contacts on SIMMs on both sides are redundant. DIMMs comprises an array of dynamic random access memory integrated circuits. The memory modules are mounted on a printed circuit board and designed for use in computing systems including hand held devices, laptops, personal computers, workstations and servers.
The DIMMs are coupled to the motherboard through connection pins located in a bottom edge. The number of pins varies based on the type of memory. For example, a 240 connector pin DIMM is used for double-data-rate two synchronous dynamic random access memory (DDR2 SDRAM), DDR3 SDRAM and FB-DIMM DRAM, whereas a 184 connector pin DIMM is used for DDR SDRAM.
Manufacturing semiconductor memory with increasing performance requires improving all aspects of the memory device. One of the bottlenecks in current memory performance is the length of the metal routings, for example, data lines within the DIMMs. The routing length between the memory chips and the DIMM connector cannot be reduced as wanted due to layout restrictions on the conventional DIMM. Routing or wiring through the circuit board within the DIMM is limited by the required arrangement of the pins. Hence, DIMMs with improved design that are compatible with existing standards and architectures are needed to overcome these limitations.